<ol>
  <li>
    <a href="https://en.wikipedia.org/wiki/Dow_Jones_Industrial_Average">https://en.wikipedia.org/wiki/Dow_Jones_Industrial_Average</a>
  </li>
  <li>
    <a href="http://www.nobelprize.org/nobel_prizes/economic-sciences/laureates/1990/sharpe-lecture.pdf">Sharpe, William, 1990 http://www.nobelprize.org/nobel_prizes/economic-sciences/laureates/1990/sharpe-lecture.pdf</a>
  </li>
</ol>
